CA2134117A1 - Method for processing residue-containing packages - Google Patents

Abstract

A method is disclosed for processing residue-containing packages so as to recover valuable materials, in particular pressure containers for dispensing polyurethane foams with propellant gases.
For that purpose, extraction with a solvent is carried out essentially in atmosphere of propellant gas and/or solvent vapours.

Description

1 ``` 2134117 . . . .
",1 40 ,;," ~ ~ W093~22077 PCT/EP93/00988 "Method ~or proces~ing residue-containing packages"

D~scription This inventiGn conce~ns a method for processing used or damaged, ~'i3; ~ residue-¢ontaining packages and recovering the valuable ~at'erials, in parti~cular rom pressuri~ed cans (aerosol cans) for dis,pensi~ng polyuret~ane foam with propellant gases, by e~tracting :them with~a;sol~ent, as:well as a plant for using this method.
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Residué-containing packages such as partially or completely emptied aerosol~cans, which occur in great quantities, are an '~ ; increasi~ng:~problem:f~r~waste disposal. They cannot be dumped in .. ,~ wa~st~e disposal~site~s ior environmental~reasons becau~e the ~i "~ r~e~s~idues;~sti~ contained;ln the cans can escape to the atmos~pher:e,~the ground, or:the~ground water where they can cause `~ ,cons:idera~bl~damage. 'The same~appiies to incineration which is :
xe~uently~not:complete:,;particularly for chemi~al-technical ~ ;products,~:and~which:~:p'roduces great quantiti~s of harmful :, ~ s~ubstances~whi~ch~aan only~be bonded,: if at all, through very expen~ive~mea~res:. ;~ n.~ofar, incineration will greatly redu~e .i ~ t~e~waste~:~volume~,~but does not~lead to a ~olution of the ef~ects on the~ ~enYironme~t ~

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~ ~; 213~117 93/22077 PCT/~P93~0098 In the following, we will discuss this problem in detail by referrin~ to tha disposal of prepolymer-containing aerosol cans for producing the polyurethane foams.

The polyurethane foams have found a wide use in many areas. In the co~struction industry, i~ particular, they are used for seali~g and insulating, but also in technical areas. As a rule, p~lyur~thane~foams are dispensed from aerosol cans ~ontaining a polyurethane~prepolymer together wlth the necessary propellant a~d,~if~ne~essary,:s:ome additives. These aerosol cans are pr~ssurized, cannot be reused and must therefore ba disposed of.
`On the other hand,'they represent a problem which cannot be ~
sol~ved through normal:~waste disposal. In addition, aerosol cans, particu~larly~older~one~s:, regularly contain f1uoridated hydrocarbons,~:whl~h~are~considered damaging to the ozone layer a~d~should~ther~fore no~t reach the atmosphere.

Wi~thin~the~f~ramewor~of the efforts~to contain r~sidential and commerc~lal waste~ creaslngly measures arS discussed and egulatio~s~p~ssed,~ whicb:force manu~acturers to take back ~hese produ~t~ a:f:ter;~se:;and~take~meas~res~for their reuse or disposal.
Thés~e~'measures~ha~e~made~it~ neaessary~ earch for ways to tr~at s~h~::waste,;~p:roduc~s~in~;:an econo~ic way.
When~pro~èsslng~thes~e returned~aerosol ca~s for polyurethan~
f~o~m6, ~:number~0~ problem~:~a~i~e~which; until now, have been ~ ~, .~
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an obstacle to an economic recycling and recovery. Some of the returned cans, for e~ample, are still under considerable pressure hecause of the r~mainin~ propellant gas, which cause3 problems wh~n shre~ding them or incinerating them. Furthermore, these cans are at d~ferent levels of filling~ rangin~ from outdated cans with practically full prepolymer content, which cannot be disp~nsed because of ~ blocked valve, to the practically emptied cans with prepolymer residues sticking to the edges, either in interlaced or non-interlaced condition. Until now, these varied conditions stood in the way of a unified method for recovering the residues.

U~til now, aerosol cans were processed in plants filled with tr~ditional inert gases because of the assumed danger of explosion during the process. The term "inert" here means non-c~ombustible. Such inert gases include nitrogen and argon.
Ho~ever, e~periments showed that the use of nitro~en inflates the gas balance enormously and has a ~egatlve ~nfluence on the eff:icient separation of propellant gas residues. In par~icular, the presence:of large amounts of nitrogen r~quires very powerful a~d thus also very;expensive condensing plants to achieve a ufficie~t s~paratio~. On the other hand, using inert gases to avoid~an explosion;in the plant is necessary.

Thus, the invention is ba~ed on the task of producing a method for processing packaging materials, containing polyur~thane prepolymers for the fo~m production, but also for adhesives " ~

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f' ~ ~ ' 21 3 4 1 i 7 W0 93/22077PCT/EP93joo988 ,f'~, ' ` '' ~ ` - 4-so that the valuabl~e materials contained therein can be recovered ; ~ without releasi~g conten~t materials that damage health and environment and~without stre~sing the proce~sing cycle with large ~4 ~ amounts of fed-in nitrogen ~ At the same time, the ~etho~ is '~ int,ended t~o meet the~r~equirement~ ~for~protection against the `,dang~er~of~exp~losi~on~

The~lnven;tion~so;lv ~t~h~s~peoblem~with~a method as described in the~beginning which~i`s,~carri~ed out essentially in an atmosphere ,,'~ o ~pEopel;lant~g~s~andil~or~'s`;olvent vàpors Preferably, this is a met~hod~which includes~the f~ol~low~ing~parallel steps '"~ Fe~e;dIn'g~the packag`ing~matèri~als~ into~a~working container whi'le~ ' at~,the~same~time,~shredd~Lng~'~them;ànd~then extracting the residues '~ t ~ s~o~l~v~en~t,~
~idue containing solution from thé working j,",~ ~ rat1,ng~the~re~ldue-conta'i~nlng~solution in this 1 ~ n~c ~ a~1ner~by~disti~ ing out ~the solvent, condensing returning;the solvent to~the working ~ n~ 'ng,,~resl~dùes ~rom~the~ w~orking container~and, o;l,lo~w,lng~u~'f~icien't~en~richme~nt,~ recovery of these residues in t ~ ~ troT~be~di~ i~ll tion container ,~ r~e~ers~to~gases~used~as~propellants-~`and foaming agent in t'radi`tional~~pressurized~cans~ /ae~rosol~cans)~ particularly th~se' '' '~for~p;roduaing~polyurethane ::f:o~am~as:~p ropell ant and~: foaming agent ~ tic ~ ,~,this~inc`ludè's~propane,~butane, dimethylether, uorocarbons~ a~'we~ as,~fl~oromethane and fluoroethane ,;`~approximate'ly~R~134a~and~R~152~a)~ às well as REPLACEMENT PAGE

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fluoridated chlorinated hydrocarbons, as far as these are still in use and licensed for use, C02, N20 etc. Nitrogen and argon are included only in that they are released from pre3surized cans were they form a component of the propella~t mixture contents.
"Pxopellant ~ases'~ in the narrow sense tha~ they used in the invention ref~r to the propella~t gas~s released from pressurized cans that are processed. It must be understood here that in the starting phase ~or the method, "propellant gases" from other sources must~be used to mak~ the plant inert. R 134a and Rl52a a~e par~icularly suited for ~his~ The extraction solvent, which is present in the atmosphere based on its vapor pressure, also plays a more or les~ significant role in rendering the plant inert. up to 50% of C02can be added to this mi~ture to protect against the dang~r of ~xplosion.

e~ have to point out here that the operational safety of th~
method depends on ~the act that: the process takes place in a c losed: system and above the explosiotl limit of all component materials that are combustible and explosiva. Insofar, it doe~
not r~st on the compl~te replacernent sf oxygen by a non-cornbust1bl ~ gas .

T~e~packaging to be processed is~preferably transf~rred via conduit into ~he working container. This ca~ be done with a tradi~tional co~duit~ which ensure~ that the container remains sealed against the environment.

If the pacl~agillg material ha~ not ~een oper~ed, it i~; useful to do this ~ durlng the feed-in and preferably along with REPLAC~ENT PAGE

~` 2134117 the shredding, e.g. in a shredder especially designed for this purpose. In the following, this is called shredding.

It is particularly advantageous to open or shred the packaging materials~by sprayi~g them with solv~nts. On the one hand, this prevents ~oaming and, on the other, possibly entered water is absorbed by the solvent~and d-istributed before it causes uncontrolled reactio~s with the content materials. This is very important parti;cularly with materials that are sensitive to mQisture:,: esp~ecially moisture-based interlacing of polyurethans prepolymers.
The shr~edded packaging material is subsequently placed onto a conv:eyor~in the work area, preferably a worm conveyor, which is sui~ted~ for separa~ing the solid materials from fluids and solvents.~ A~magnetic~conveyor:system must be considered if these packaging~mat~erials are:ferromag~etic. A combi-nation of both conYeying meth~:ds may~also be use~u~l, particularly if the pa~c~aging-materials consist of tinpla~e wit~ plastic cQmponents, hich ls~oftèn the~ca~e with aerosol cans.~

E~traction~of~the~residues from the opened and/or shredded ackaglng material :ta}ces place in~the working container with a sol:~rent that ~is spe~ifically designed ~or the respectiYe residue.
In ;~ny~case, ~suitable solvents~ a~re those used to produce the packaglng con~tent: originally and/or those still ~ontained in the packaging materia1s.

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~:i 46 ~O 93/22077 PCT/~P93/00g88 On the one h~nd, extraction may take place by dropping the opened and/or shredded packaging materials into a working container ~: filled with solvent and:leavlng them there for a period before they are moved along. The parallel alternative is to spray the packaging materials during the shredding and/or the conveying proceA~s with fres~h solvent and then washing them. It is useful to bring the packa~lng materials in all three stages in contact wi~h the solvent, that is to spray them during the shredding and conveyi~ng as well as subjecting~them to solvent in the working container, for exa~ple in a catch funnel for the worm conveyor.

Subsequent to removing them, the solid residues are then dried in a~y:optional sequence,~are brought out on the conveyor and then ~ sorted and:mo~ed toward the recycling area.
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The traditiona1 est~rs, ketones, aliphatic and aromatic :hydrocarbons~and their derivatives are particularly well suited a~ solvents,~ especially those with a boili~g point of about 200~C. :If containers with polyurethane prepolymers are ~ p:~ocessed, then:acetone and toluol are particularly well suited v~ ~ as so:lvents;.

:Large amounts of propellant gases are released during the proc~sqing o~ residue-containing sprayr pressuri~ed and aerosol cans. ~It~is~not desirable that these gases escapa to the atmosphere. If these propellant gases are not needed as inert ii; gases,~they are collected and condensed with suitable means.
Such~a condensation on the one hand may take place through f ~

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.`''9 ``` 2134117 compression until the gas li~uefies and on the other by condensing out under low temp ratures. These ~easures are use~ul, particu1arly ~or propellant gases that can be liguefi~d such as low boiling point fluorocarbons or e~en combustible hydrocarbons such as propane or butane.
The inv~ntion method transfers the residue~containing solution in :the working containe~r to a distillation container with, fsr example, a pump. In the~distillation ~ontainer, the solution is further condensed. To do this, the solution is heated up and the solvent distilled out of the liquid phase. It may b~ useful to work with reduced pressure to reduce the boiling temperature and avoid displaGements in the residues. The distilled out solvents are~condensed and, following this cleaning through distillation, a:re returned to the processing cycle if ne~essary. The residues in~the distil:lation container liquid are drawn off after they are su~i~cientl:y condensed:and removed for further processing.

In case the~method in this inYention is used to process aerosol ca~s with polyurethane:prepolymers,~ it is useful to add ~ known th:inner to increase the flow capacity of the prepolymers that collect in the distlllation container. Such a thinner should have a higher boiling point th~n the respectively used solvent.
Parti:cularly-suited for this is trlethylphosphate or fresh raw material s~ch as the raw materia1s used originally to fill the packaging l material~ . ', REPLACE~ENT PAG~

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~1~4117 : 48 WO 93/2~077 PCT/EPg3/00988 9 _ The invention method is carried out with protective gas.
Protective gases are the previously listed "propellant gases" and C02~ C02-containing combustion gases and others like it, whereby the displacement of o~ygen i~ the processing range is particularly important to avoid an explosive mixture. If a stored propel lant gas admixture such as C02, R 134a and R 152a is used, it is useful to circulate it, whereby at suitable stages, propellants that are released from: pressurized cans and eYaporated solvents are separated out.
Or~e special advantage of the inventive method that it can b-~ run continuously and, with slight modifications, can be adapted to a multitude of pressurized canlaerosol c:ans now on the market.
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Thus, ;the inventive method~ makes ls possible, for example, to process residues-containing polyurethane prepolymers from aerosol cans and other containers and recover these so that they can be reused while, at the same time, recovering the raw material for the containers in a r~latively clean form so th t they can be re~c:ycl ed or sent to a waste dump . The prepol ymer, which i~
~ énriched~ and concentrated during the~ proces in the di~tillation `~ ontainer can b~ used for many purposes. For instance, it can be used as adhesiv.e, dissolved in toluol or another solvent, or as bonding~ag~nt for composite materials gr as coupling agent for ;~ :the;:produc;tion of molded parts made from reeYcled products such a ~ vinyl:tiles made of granulated~old tires.

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21~1117 4g ~ WO 93f22077PCT/~P~3/00988 :~ -10-In the course of this m~thod, the residues from aerosol cans or . contai~ers are moved to the working container and submerged in 'ii!`. ~ th~ solvent therein. As a result of the feeding in of residues : lnto the workin~ container and return ~f distilled solvent, the volume inside the conta1ner rises above the operating volume : during which solvent is moved from th~ working container to the distil lation cos~tainer . On the whole, there is a constant volume of solvents and dissolved residues in the working container~
~ i With a suitable medium, the distillation container is heated until the solution inside is boiling and a continuous solvent is distilled out. This solvent is then condensed with a cooling agent and returned directly or indirectly to the working container so that this container always has ~resh solvent for dissolving the residues that are conveyed in. In this way, the residues that en~er the working container are extracted continuously with 5QlVe~t. The extracts become concentrated in the distil-l:ation container b~cause ~he solvent there is removed continuously and will be recovered from there once they are concentrated enough ~ Insolubl e residu~s that remain in the work:ing contain~r are drawn off from th~re at certain intervals.

The us~ of the inve~tive metho~ is particularly advanta~eous for the recovery of prepolymers from aerosol cans for the production of polyurethane foam. The aerosol can empties via an adapter into the working contalner. However, it is more advantageous to .open ~he cans and extract the contents in the working container.
It is preferable to shred the aerosol can inside ~ REPLACEMENT PAGE

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WO 93~22077 PCT/EP93/00988 the working container in a specially equipped device, such as a ~shredder. The shredding residues can be removed fro~ the working container with a magnet because aerosol cans usually consist of tinplate, or with a worm conveyor, as mentioned above.

~Ester, ketone, apliphatic or aromatic hydrocarbons or their derivatives with a ~o1ling point of about 200 C are particularly ~: :: sùited as solvent for the extraction. Alkyl ester of monocarboxylic acids and ketones with up to 8 carbon atoms, as well as alkyl benzene~with up to 10 carbon atoms are especially ~:: suitable. Acetone, ketone, toluol and xylene are preferred. If the extracted prepolymer subseque~tly is to be used for adhesives, it i~ aduisable to use toluol because adhesi~es based n~polyurethane are frequently u~ed in toluol solution. In addition, solv~nts of polyurethane prepolymers in toluol have a comparably low viscosity.

A:t:hinner may be added to the dlstîllation container which ensures or improYes the ~low~bility of the ~ransferred and concentrated prepolymer. If the thinner is added at the start o~
;~ he e~traction already, it must have a higher boiling point than :the solvent so that it~does not become depleted during the :è~traatio~. Ge~erally ussd thinners for prepolymers are rialkylphosphate, particul arly trlethylphosphate, or other raw materials ~hat:~:correspond to:the original material.

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~; 1 : With the inventive method, the propellant still contained in the aerosol cans - as ~ rule fluoridated chlorhydrocarbons, partially halogenated hydrocarbons, dimethylether, propane, butane, etc. -is collec~ed and recovered if it is not used to render the plant inert. For th~s ~urpose, the gas flow coming from the worklng container can be condensed so that the propellants in it are liquefied. A~ an alternative, the propellants can be condensed b~ cooling them and collected in a cooling trap.
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~:~ The inve~tive method is suited for batch quantities as ~ell as for a continuous process. However, a continuous operation is recommended because of the still high investment costs.
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Furthermore, the invention cor.cerns a plant for use with the ~:~ inventive method. 5uch a plant includes an incoming conduit, a de~ice for opening tha fed-in packaging materials, a collection container ~or the opened materials, at least one each feed-line : for fresh solvent and protective gas, one discharge for solvent co~taining soluble packaging residues, one~conveyor for solid packaging~residues as well as at least one solvent spraying nozzle that is directed toward the device for opening th~
~;~ pac~agi~g materials~ Peripheral equipment for recovering the solid and dissolved packaging residues, recovering the solvent as well as a trap ~or propellant gases released from the packa~ing materials are also connected ~: ~

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,,t; 21~117 ~ .'t ~: NO 93~22077PCT113P~3/00988 :The device for opening the fed-in packaging materials, which is ~: used in the plant, consists of a traditional ~shredder with two ~: counter-rotating dr~ms equipped with cutting blades. It is ~t`~ essential that such a shredder or any other device for opening the packaging materials is sprayed with solvent during the ,!"~: proce~s of opening so that all released residues are absorbed directly in by the solvent. This avoids a foaming up of the conten:ts if it con~ains propellants,~ but also the sticking to~e~her. At the same tlm~, any water adheri~g to or which has e~tered the packaging material is distributed by the spraying so ~: that an uncontrolled reaction between the water and any released ~packaging content is avoided. This is particu~arly important ~ during the~pro es~ing of packaging materials containing ;i ~ :polyuretha~e prepol~ymer, which interlaces uncontrollably if there t`~ ~ i s water presen~ and can gum up the opening device. In the presence of~ sufficient~ amounts of solvent~ thP concentration o~
water~that~has~entered ca~ be reduced to a level where an un~co~troll:ed reaction is impossible. Any interlacing that might still occur wi}l~sta~y in the tolerable range.

t~is useful to;h~ve at least one spraying no~zle above the shr:edder.~ t is particularly advantageous if during the process ,`~n~'l ~ Of~ opening the contalners, the ope~e~ is sprayed with solvent ~ ~ f~rom ~;top~ and bottom: with at leas:t one spray nozzle. Following .~, ~ the~:shredding,:~the packaging materials, together with the i~ ~ sprayed-on solvent, are transferred to a collection and .! ~ e~trac~ion contai~ner from which the dissolved and/or liquid ~ components ar~ discharged ,`! ~
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~ia a line a~d the solid re~idue~ are removed by conveyor.

It is useful if the conveyor is a worm conveyor which projects into the lower part of the collection container filled with solvent and removes the solid co~ponents from there~ This ~orm conveyor is preferably sprayed with fresh solvent from one or more spray noz~les to wash off any packaging residue solution still clinging to the solid packaging residue that is removed.
Th~ washed conveyor ~aterials is then moved through a drying pLant and removed via an outgoi~g ~onduit from the plant.
Subs~quently it i5 moved to ~nother place for further sorting and reuse.

Th~ solvent used in the inventive method is effectiYely recirculated. This requir~s a ~ontinuou~ removal o~ the solvent from the ~xtraction and coll~ction container, distilling out of the dissolv~d content materials and, following condensa~ion, feeding the solvent ~ack into the plant via a pipe s~stem and the spray ~ozzles or, i~ ne~essary, the washing de~ice.

In accordance ~it~ the inventive method, the plant is run with protective ~as, as described abo~e, If'the protective gas i~ not released from the pac~aging materials themselves, it is piped in n~ear th~ opening device and is drawn off again from the ext~actio~ and working container and/or th~ dryiny plant. In order to a~oid add~tional costs, the protective gas can be recircul~ted. It is usefu1 in that cas~ to e~uip the protective .j: ~ ~ :
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r 2 1 3 4 1 1 7 ~ 54 .~WO 93/22077 PCT/EP93/OOg88 gas circulation wi~h a device to separate out aerosols, moisture, : propellant gases that were carried along and absorbed solvents.

It is useful to load the conduits with inert gases via separate lines. T~is lS the only time it makes sense to use nitrogen, ar~on or C02 to prevent unwanted gases f rom escaping to the nvironment.
Th~ inventio~ is explained in more detail in the enclosed drawings (preferred form), which show as follows:
~5 ~ FLg. ~1 A laboratory-type recycl~ing pla~t for illustration.
:Fig. 2 A technicaI plant according to the invention.
Fig. 3 A detailed representati~on of the plant in FigO 1.
Figur~e 1 shows a labQratory-scale recycling plant for polyurethane foaming agent. Inside a three-necked flask 1 with feed-in 2 and an overflow 4, as~well as a vertical tube which ends in a reflux condenser 3~ is the e~traction solvent, to which ::the contents:of not completely empty aerosol cans for the PU foam prod,lction :is a:dded ~ia a f eed-in 2 and an adapter tha~ is not shown. A hollow magnet 10, which is moved with a magnetic , ~ stirrer 9, ensures continuous mi~in~.

The solution frorn fl:ask 10 is transferre~ to liquid flask 6 via overflow 4 in l:h~: same amounts at whi h material is added via fe~d-in 2: to the three-necked fl~sk. A shut-off val~e 5 ensures il ' ~
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W0 93/22077 PCT/EP93~00988 that there is a continuous ~upply o~ solution. The liquid flask 6 is heated with a heated ~th 7 until the solution inside is boiling and evaporated soivent is distilled out via a tube 8 which connects to the reflux cooler 3. The solvent without extract that condenses at reflux coc,ler 3 drips back into operating flask 1, where it again participates in the extraction and,~at the same time, effects a transfer o~ solution to the liquid flask 6.
The wo~king:o~ the~inventive~method in the ~bove-described a~paratus starts with the preparation of operating flask 1 which is filled, ~or e~ample, with acetone as solvent. Parallel to that, a small ~mount o~ thinner such a triethylphosphate is fill~ed;into liquid ~lask 6 along with another solvent 50 that the colleGtlng prepolyme~ in it remains free-flowing.

Subseguently, the cycle is started. The liquid fl~sk 6 is heated to about 90 C and ~Xe reflu~:cooler and magnetic stirrer are activate~ After about 15 min., a system cycle ha~ balanced out, mea~ing as~much sol`vent as evaporates from liquid flask 6 via the disti~llati~on bridge 8 into reflux ~ooler 3, condensates ther~ and drips~into operating;~fla~sk I. From there, the solvent circulates :via~over~low 4 and shut-off ~alve 5 bac~ to liquid flask 6. The crcl~e IS~ c:loeed. ~:

As~soon;as a~baIance has been established, PU foam is fed into operatin~ fla~k 1 via th~ feed-i~ tube 2 and a~ adapter which is not depiated. There,:the foam dissolves immediately, the REPL~CE~M~T PAGE

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~6 : W0 93/22077 PCT/EP93/00988 ~prepolymer dissolves and the propellant escapes through cooler 3 and is deposited in a cooling trap (not shown~ at its upper ~nd.
~' The fed-in prepolymer ~olume flows as a thinned solution via the ~ ov~rflow 4 into liquid flask 6. There, the prepolymer is I ~: enriched to the same degree that PU foam is sprayed via feed-in I
tube 2 into the operating flask 1 and is then transferred wo the iquid fla~k as a thinned solution. The free-flowing solvent, on the other~hand, is in the cycle and is returned again and again `from the:~liquid~flask to the operating flask.
A~ the~end o the operating:cycle, a prepolymer solvent mixture rich in prepolymer forms in llquid flask 6. Closing the shut-off valve will prevent new solution ~rom ~lowing into the liquid flask:so that th~ prepolymer can be condensed further through distillation. The prepolymer is drawn from the liquid flask once it:~has~reached the desired concentratlon and/or enrichment.

It is~natural that not: only the prepoly~er component ~rom the a:e:rosol~cans will be enriched in ~he liquid flask, but also the inherent addi~tives and:catalysts. As far as the product is again used~to~:form:~polyurethane, these~substances do not cause any probl;ems.~ f it~ is used for~'other purposes, these substances can be~:remov~d~at least partially through distillation under normal pressure~or~in~:a va~cuum~through extraction with:solvents, which ~ ~do.~not dl~solve~the:~polymer and do~not react with it.

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`~ 2134117 .
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WO g3f22077 PcT/Epg3Joo988 ~igure 2 shows a dlagram of ~hs processing sequence inside a ;~; plant for prepolymer recovery from packa~ing containing prepolymers, particularly aero~ol cans, which i~ operated according to the inventive method. This method can be used to 1 process other packaging materials as well, without modifications apparent to the e~pert.
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The plant as shown in Figure~2 consists of three stages, the mechanical processi~g, the prepolymer recovery and the propellant r~covery. In the mechanical processing stage, ~he delivered packaging materials first pass through an initial storage area and then reach a charging station where the packaging is freed of foreign materials and plastic components and is also pre-dried.
They are then fed into a shredder l2 via a metered addition with a scale and an input conduit 11. In the shredder, they are shredded while being ~prayed with solvent and transferred to : working container 13. In this working ~ontainer, the shredded packa~ing mate~ials are washed with solvent and separated from ny soluble components. Th-e solid -omponents are removed via a conYeyor 14: ~hile ~ing sprayed continuously with solvent and are then:fed into ~dryi~g plant 15 and subsequently removed from the operating ~ycle via~a conduit 16. The solvent evaporated in the drying plant lS is cond~nsed and re~urned to the process. After b~ing removed, the shredded solid ma~erials are sorted according :to,material type and moved to a recycling facility.

.iJ ~ The solvënt collei~e~ in worki~g container 13 and all residues J~ ~ di~solv~d ~herein is conducted through line 17 to a receiving ~,: REPLAC~MENT PA~E

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~O 93/2~077 . PCT/EP93/OOg88 -lg-~: c~ntainer 18 from which the solution is then piped to the distillat.ion plant. There, the solution is distilled out, if ~ necessary under low pressure. The distillation residue is then ,1 drawn off, adjusted and conditioned for furt~er use and returned to the economi.c cycle. Residues which cannot be reused can either ~e burned or deposited as concentrate on a disposal site.

The solvent distilled out of distillation plant 19 is condensed ;~ .
in a ondensation plant 20 and r~turned to the cycle via a s~orage tank 21 and line 22. Solvent losses are balanced by fresh solvent. The condensed solvent travels from storage tan~
21 ~ia ~pray nozzles (see Fig. 3) to shredder 12 and conveyo:r 14 back into working container 13.

L~ike the; extraction and distillation, the shredding inside shredder 12 is done in the presence of protective gas, piped in via line 24. Normally, the accumulating propellant gases are su$fici~nt ~to cov~r the protective gas naed during the plant operation. ~A ~ePd-in~via ~ine 24 is needed, in particular, if :mo~st:ly empty~pres~urized:cans are process~d or if the plant is star`te~. ~he ga~ component released duriny shreddi~g i~ led tog~ther:with the protective gas flow via line 25 and, if appl~icable,~:~an aeroaol~separation plant and drying plant 25a to a aondensation faci:li~y 26.~ There, in a first ~tage 26a, adherin~
olvent~ is ~ sep~rated out and fed :into a storage container ~7 which is connected:via line 28 with the solvent tan~ ~1 for condensing plant~ 20.~ ~ln ~ second stage 26b, the propellants : ~

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~0 93/22077PCT/EP93/00988 are conden~ed, recovered and collected in a tank 29 if they are not used ~s prote~tive gas for the plant. Propellant gases which are collectin~ in distillation plant 19 can also be fed into the propeilant condensing plant. A portion of the propellant gases is returned from the condensing plant to the processing plant ~, ~
nd, if necessary, replenished from storage tank 35 via line 24.
3: Conduits 11 and 1~ each are supplied via lines 32 and 34 with nitrogen from liquid gas tank 30, whi~h arrives either after ~ ~ passing through a distiller 31 or heat exchanger 26b.

3; It is useful to condensate the propellants from line 25 in condenser 26b with the aid of fresh and cold li~uid nitrogen supplied via line 33 from li~uid gas tank 30. This nitrogen is subse~uentl:y fed into conduits ll and 16 via lines 34 and 23.
Propellant gas compon~nts which are no~ condensed and do not cause damage are released into the atmosphere near tank 35, following co~densation, if the protective gas need of the plan~
i5 met.
Figure 3 shows ~an inventive plant for mechanical processing of :~ :residue-containing packa~ing materials. This plant consists vf a i ~ , materia:l feed and a conduit ll, which is filled with packaging materlals r~ady ~o:r~processing via a traveller lla and which r~leases~ the fed-in:packaying materials via a second traveller llb to ~he act:ual pl:ant~ Conduit 11 is ~illed with nitrogen via ~ line 23.

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~ ; 21~411;7 !,`.~' 60 ~ o 93/22077 PCT/EP93/00988 ,; ~ 21-, ; ~: ~ Below conduit 11 is an opening and/or shredding device consisting ..
of two motor-driven (M) and counter-rotating drums, which shred ~ ~ the fe~-in p~ckaging materials with their attached cutting blades !:, ~ or similar cutters. Two spray ~oz~lies 41~ and 41b for spraying s:olvent onto the surfac~: of the rotating drum are arranged above the shredder. Solvent is sprayiPd onto the shredded materials in the same:way:with spray no~les installed at an angle below the shredder drums.

Sp~ay~:nozzles~41~, 41b as~well as:42a and 42b are supplied with fresh ~olvent via feed~ nes 22 and 22b, which is transported after spraying, together with the~shre~ded materials to the extrac~ion~and worki~ng container 13 below t~e shredder 12.
~:Çontaine~r:13 holds~the~extractionl~solvent mixture together with ~ the~solld:~componen:ts~o~ the packaging materials. A motorized ,ii ~ s~ti~rre~r 44~en~sur~es that solid:re~idues and solvent are in close ~: ~ contac~t~and~the:extr~ct:ion is~effeGtive. The extract is pumped i~ rom;~c:ontainer~1:3 with a motoriz~d pu~p 45, through a line 17 and :,i ~ into:~storage~contain~er 18 for prepolymer recovery, which is shown ~ in~F1gure:~:2~
,s ,~
A:~worm conv:e~y~r~14,-t~h~ lower~end of which lS submerged in the `~ e~xt~ract/~o~lv~nt~mi~tur~e~, re~oves~s~olid packaging residues from ~:G~ai~er~ ~13. :~To~remove~-ext~ract~f~rom the solid packaging mate~rl~al~res~idue~,~these~are~m~ved~with the worm conveyor through ~:; ~ a:washlng~segment which contains spraying noz~les 43 that are po:inted tloward the~oll~eyor. Spraying noz21e~ 43 are suppliled ~EPLACEMENT PAGE

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~ 93/22077 PCT/EP~3/00988 ~ith fresh solvent via lines 22 and 22a. The solvent i3prayed onto worm conveyor 14 travels to cont~iner 13.
~, The solid packaging residues moved along with worm conveyor 14 are fed via a batch funnel into a drying fa~ ty 15 where a onveyor 46 moves the solid residues along under a heater 47.
From there, the materials are moved to a discharge conduit 16.
This: conduit 16 is sealed on the plant side with a slide 16a and on the :solid material processing side with a slide 16b. Nitrogen ~, : c~n be fed into conduit 16 via a line 23a.
,1:
The processing plant consists of a motorized conveyor 48 which ransports the materi~l through a magnetic separ~tor ~9. Wi~h ; the aid of this magnetic separator, the m~terial is se~arated according ~o its magnetic qualities.
, ~

Th~ inve~tion-base~ plant according to Fig. 3 - with the exception of the c04duits - lS operated w~ith protective gas.
Thiis protecti~ve gas iis fed via line ~4 into shxedder 1~ and diatribu~ted throughout the plant.; Any protective gas leaving the plant~, whlàh contains salvents and small amounts of nitrogen from the~condu~ts, is drawn off ~ia lin~ 25 ~rom container 13 and/or via line~5~a~from:the dryin~ facility 15 for solid packaging esidues. lt may~be~useful to recirculate the protective gas if the:amount of gas collecting from the pressurized cans i~ low.

It i~ u-~eful to have motorized valves in all lines if it is necessary to regulate the flow of material in them.

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~? 2134117 ~t ! 62 .~
WOg3/22077 PCT/EP93/00988 This is particularly true for the solvent feed-in lines ~o the ....
~ spray nozzles and washing facilit}es, thet operation of which can t'j~`: be:stopped as soon as the material feeding and/or removal of ~ solid residués is finished.
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L~ the pre~cedlng~descriptlon, the terms propel~ant, propellant gas, protective gas and inert gas are used interchange~bly, insofar~as~the operation of the actual plant is concerned. With ~ respec~to the conduit arrangement, thP protective and/or inert < ~ gases~are~un~ersto~d:to~be traditional protective gases such as 1, ~ nitrogen and argon~
1, I ~
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~ The facili~ties a~d plants used~for~the inventive method are i! ~ commer~i`a~ y:~avail~ab~le or can be retrofitted by an expert to suit this~purpos~ through~simple:~modification or adaptation of known ~!,J ,,',~ facilities~and:p~lants.~

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Claims (20)

1. Method of processing residue-containing packaging materials to recover valuable materials, especially from pressurized containers for spraying polyurethane foams with propellants, and extracting with solvents, with the following parallel steps, taken in an atmosphere consisting essentially of propellants and/or solvents vapors:
Feeding the packaging material into a work container while simultaneously opening them up and extracting the residues with a solvent, transferring of the residues from the work container into a distillation container, concentrating of the residue-containing solution in the distillaiton container by distilling out the solvent, condensing of the processed solvent and returning it to the work container as well as Removing the packaging material residues from the work container and, after adequate enrichment, recovery of the residue in concentrated form from the distillation container.

2. Method according to Claim 1, characterized by the fact that the packaging materials will be shredded to open them up.

3. Method according to Claim 2, characterized by the fact that the packaging materials will be shredded and, at the same time, sprayed with solvents.

4. Method according to one of the stated claims, characterized by the fact that solid shredding residues will be removed from the working container with the aid of a conveyor, preferably a worm conveyor.

5. Method according to one of the Claims 2 to 4, characterized by the fact that ferromagnetic shredder residues will be removed magnetically from the work container.

6. Method according to one of the Claims 2 to 5, characterized by the fact that the shredder residues will be sprayed with solvent while they are removed.

7. Method according to one of the stated claims, characterized by the fact that ester, ketone, aliphatic and/or aromatic hydrocarbons with a boiling point of about 200° C will be used as solvents.

8. Method according to Claim 7, characterized by the fact that acetone or toluol will be used as solvents.

9. Method according to one of the stated claims, characterized by the fact that the solvent will be distilled from the distillation container under reduced pressure.

10. Method according to one of the stated claims, characterized by the fact that the gases contained in the packaging material, in particular the propellants and, if applicable, the solvents, will be separated and extracted.

11. Method according to Claim 10, characterized by the fact that the gases are condensed.

12. Method according to one of the stated claims, characterized by the fact that it is carried out with a released propellant gas as protective gas, preferably propane, butane, dimethylether, fluoridated hydrocarbons and/or CO2.

13. Processing plant for applying the method according to one of the stated claims with an intake (11) and an exit (16) channel, a device for opening up the fed-in packaging material (12), at least one each feed line for fresh solvent (22) and the protective gas (24), one conduit (17) for soluble packaging material residue-containing solvents, one conveyor (14) for solid residue and at least one spray nozzle (41, 42) for spraying solvents, which is directed toward the device to open up the packaging material (12), characterized by an extraction and collection container (13) for the opened material, an distilling plant (19) for distilling out the solvents, one condensing plant (20) for the distilled solvents, one return pipe (22) for condensed solvents as well as the equipment for recovering the dissolved packaging materials.

14. Plant according to Claim 13, characterized by the fact that the device for opening the packaging materials (12) consists of two counter-rotating cutting drums, which form the shredder.

15. Plant according to Claims 13 and 14, characterized by the fact that at least one spray nozzle (41a, 41b) is attached above the device for opening the packaging materials (12) and is pointed toward it.

16. Plant according to one of the Claims 13 to 15, characterized by the fact that at least one spray nozzle (42a, 42b) is installed below the device for opening the packaging materials (12) and is pointed toward it.

17. Plant according to one of the Claims 13 to 16, characterized by a worm conveyor (14) for removing the packaging material residues, which projects into the collection container (13).

18. Plant according to one of the Claims 13 to 17, characterized by the fact that nozzles (43) for spraying solvents are installed above the conveyor for solid packaging material residues and are pointed toward it.

19. Plant according to one of the claims 13 to 18, characterized by a drying rack (15) which joins the conveyor (14).

20. Plant according to one of the Claims 13 to 19, characterized by separate protective gas lines (23, 23a) in the area of the conduit (11, 16).